What electrical renovation work is allowed in an HDB flat?

HDB electrical renovation rules

HDB's electrical works guidelines say all wiring installation work must be carried out by an LEW licensed by EMA. EMA says electrical work in an HDB flat needs a Licensed Electrician, the class of LEW approved for loads of up to 45kVA. Its guide to engaging Licensed Electrical Workers lists wiring, power points and circuit breakers among the work an LEW should carry out or supervise.

Extra 13amps power points, lighting or fan points, extending wiring and rewiring need no HDB permit, with no limit on the number of items, subject to your existing main switch rating (HDB electrical works). The no-embedding rule still applies, and SP Services Form CS/5H endorsed by HDB must be submitted for testing of the new wiring.

You are responsible for renovations in your flat and must make sure your contractor follows HDB guidelines, says HDB's renovation information page. To see which jobs count, read what work needs an LEW, or compare HDB electricians.

Concealed or surface wiring

HDB does not allow embedding wiring, or wiring housed in metal or high impact PVC conduit, in reinforced concrete slabs, beams, columns, walls, wall plaster or other finishes (HDB electrical works). Under HDB wiring rules, concealed new wiring in walls is not allowed. Covering wiring with PVC trunking, or encasing surface wiring in metal or high impact PVC conduit, needs no HDB permit.

If you want new wiring out of sight, ask whether it can run above a false ceiling or behind carpentry; HDB does not allow it to be buried in the wall. Ask your electrician and carpenter how each run will be routed before the carpentry is built.

Hacking, chasing and fixings

Chasing means cutting a groove into a wall to bury a cable. Because HDB does not allow new wiring to be embedded, chasing walls for new wiring is not an option in an HDB flat. HDB's electrical works guidelines also say power-driven nails and screws must not exceed 6mm in diameter and 40mm in penetration depth, so ask how trunking and fittings will be fixed.

HDB's renovation information page says all demolition and hacking of walls, partial or complete, needs HDB's prior written approval. General renovations are allowed from 9am to 6pm on weekdays and Saturdays, with none on Sundays and public holidays. Restricted (noisy) works, such as heavy and excessive drilling, are allowed from 9am to 5pm on weekdays only, not on Saturdays, Sundays, public holidays or the eves of New Year's Day, Chinese New Year, Deepavali, Hari Raya Puasa and Christmas Day. The renovation hours checker helps you plan around these.

Permits, isolators and the main switch

HDB's electrical works guidelines say a new 15amps power point or 20amps isolator needs an HDB permit in flats provided with a 30amps main switch. Flats with a 40amps main switch need no permit. Blocks completed since 1994, or upgraded under the Main Upgrading Programme (MUP) or Home Improvement Programme (HIP), have a 40amps main switch.

HDB also says appliances rated above 15amps are not allowed, a 20amps isolator is only allowed for aircon installation, and a ceiling fan needs no permit if it weighs no more than 6kg with at least 2.4m clear height from the floor to the blades (HDB electrical works).

Check your flat with the renovation permit checker, and see planning electrical points before renovation to decide where sockets and isolators go.

Certification at the end

HDB says that upon completion of electrical renovation work, you apply to SP Services for testing through your LEW (HDB electrical works). EMA's electrical safety page says new wiring, rewiring and extensions have to be tested by an authorised officer from SP Services Ltd before supply can be turned on. The LEW also inspects and certifies that the installation is safe. You can check a worker's licence on EMA's ELISE portal or by calling 6835 8075.

Planning a full rewire? See the HDB rewiring cost guide; the price depends on the job.

When to stop and call a professional

EMA's electrical safety page says not to use cracked or broken power points and to have damaged ones replaced by an LEW. HDB's guide to electrical accessories and wiring links overheated plugs or frequently blown plug fuses to loose connections, overloaded circuits or broken cables. If you notice these signs, compare electricians and ask an LEW to check.

HDB also gives the estimated average lifespan of a PVC electrical cable as about 25 years, and an LEW can check the wiring and advise whether it needs replacing (HDB wiring guide). If you are considering rewiring, see electrical costs; the cost depends on the job.

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